Thank you for your query.
If I understand you correctly the problems with your child are:
but did not have an asthma attack last night
2. Sinus infection
for which having amoxicillin
3. Shaking body for about 30 seconds every few minutes
4. No fever
or any other problem
If the abnormal movements of the body are still continuing then I suggest that you fix up an appointment with your doctor and get him examined immediately. However, if the movements have stopped then you can discuss this issue with your treating doctor and follow his instructions.
If these movements occurred during an asthma attack then they can be attributed to low oxygen
supply to his brain during an attack. This needs to be addressed urgently to prevent any damage to the brain due to low oxygen supply.
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.